Research on the Mineral Selenium
The following articles are presented as a reflection for
the use of ionic minerals selenium as a dietary supplement and nutritional supplement. You
will find more on selenium here. You can also
purchase this diet supplement below.
Ponz de Leon M; Roncucci L
Dept. of Internal Medicine, University of Modena, Italy.
Scand J Gastroenterol Suppl (NORWAY) 1997, 222 p72-5
Chemoprevention can be defined as an attempt at cancer
control in which the occurrence of the disease is prevented by the administration of one
(or more) chemical compounds. Main problems in chemoprevention studies are the choice of a
suitable drug, the choice of an appropriate intermediate or definitive end point, and the
definition of the population which should be investigated. Main classes of chemopreventive
agents include vitamins, non-steroid anti-inflammatory drugs, minerals such as calcium or selenium, and other antioxidants such as N-acetylcysteine.
Chemoprevention is particularly appealing in colorectal cancer, either because these
lesions develop through a multistep process, or owing to the concept of "field
carcinogenesis'. Between 1985 and 1990 we carried out a controlled study in which
antioxidant vitamins or lactulose were used in an attempt to prevent the recurrence of
colorectal polyps after their endoscopic removal. Among the 209 patients who could be
evaluated, polyps recurred in 5.7% of the individuals who were given vitamins (A, C and
E), 14.7% of patients given lactulose and 35.9% of untreated controls (chi 2 = 17.1, P
<0.001). The study suggested that either antioxidant vitamins or lactulose could be
effective in reducing the recurrence rate of adenomatous polyps. In a subsequent on-going
study, lower doses of the same vitamins were tested versus N-acetylcysteine (60a 40%
reduction of the recurrence of polyps versus controls) in individuals given
N-acetylcysteine, while the effect of lower doses of vitamins was less appreciable.
Definitive results of the study should be available by the end of 1998.
Mukherjee B; Sarkar A; Chatterjee M
Department of Pharmaceutical Technology, Jadavpur University, Calcutta, India.
Eur J Cancer Prev (ENGLAND) Dec 1996, 5 (6) p455-63
Supplementation of selenium in
the form of selenomethionine (8 ppm) in drinking water daily has been found to be highly
effective in reducing cancer incidence in male Sprague-Dawley rats fed
2-acetylaminofluorine (2-AAF) (0.05%) in the basal diet daily for 16 weeks.
Selenomethionine treatment before initiation, during initiation or during the
selection/promotion phases of hepatocarcinogenesis has been found to be effective in
elevating hepatic microsomal cytochrome b5, cytochrome P-450 contents, triphosphopyridine
nucleotide-cytochrome c-reductase and cytosolic aryl hydrocarbon hydroxylase activities to
a statistically significant level measured either in the hyperplastic nodules or in the
non-nodular surrounding liver parenchyma compared with 2-AAF control rats. Moreover,
selenomethionine treatment throughout the study also decreased the cytosolic
1-chloro-2,4-dinitrobenzene conjugated glutathione-S-transferase and microsomal
UDP-glucuronyl transferase activities to a significant level when compared with 2-AAF
control rats. Furthermore, direct correlations between hyperplastic nodules and
non-nodular liver areas were observed with the hepatic selenium
content and also with the rates and patterns of hepatic drug metabolism. Selenomethionine
was also found to protect and improve the histopathological indices without any toe
haematoxylin and eosin staining. Our results establish the fact that selenium
is particularly protective in limiting the action of 2-AAF during the initiation phase of
hepatocarcinogenesis.
Badmaev V; Majeed M; Passwater RA
Sabinsa Corporation, Piscataway, NJ, USA.
Altern Ther Health Med (UNITED STATES) Jul 1996, 2 (4) p59-62, 65-7
Selenium is an essential trace element in nutrition for the
prevention of disease in humans. Epidemiological studies indicate an association between
low nutritional selenium status and increased risks of
cardiomyopathy, cardiovascular disease, and carcinogenesis in various sites of the body.
The role of selenium supplementation in the prevention and
treatment of AIDS-related pathology has been considered. Selenoproteins discovered in
mammalian cells may account for the essentiality of selenium
in the body's antioxidant defense; thyroid hormone function; immune system function,
particularly the cellular immunity; formation of sperm; and functioning of the prostate
gland. The seleno-organic compounds, primarily L-(+)-selenomethionine, generally are
recognized as safe and effective forms of selenium
supplementation. The nutritionally recommended dose of elemental selenium
is estimated at 50 to 200 mg per day. There is, however, increased discussion of a
pharmacological dose of selenium, significantly higher than
the nutritional dose of the microelement, to treat active conditions. One way of
increasing the tissue levels of selenium is to combine its
ingestible form with a nutrientilability enhancing compound. (87 Refs.)
Neve J
Universite Libre de Bruxelles, Institut de Pharmacie, Belgium.6277
J Cardiovasc Risk (ENGLAND) Feb 1996, 3 (1) p42-7
Selenium is a powerful antioxidant regulating the activity
of the glutathione peroxidase enzymes, which catalyse the detoxification of hydrogen
peroxide and organic hydroperoxides. Selenium deficiency has been implicated in the
aetiopathogeny of Keshan disease, an endemic cardiomyopathy observed in China, and in
other cases of congestive cardiomyopathy in subjects on artificial nutrition. However, the
evidence from case-control and prospective studies for an association between low selenium status and cardiovascular diseases remains controversial.
Mechanisms whereby selenium protects against such diseases
include increased resistance of low-density lipoproteins against oxidative modification,
modulation of prostaglandin synthesis and platelet aggregation, and protection against
toxic heavy metals. The therapeutic benefit of selenium
administration in the prevention and treatment of cardiovascular diseases still remains
insufficiently documented.
Vitoux D; Chappuis P; Arnaud J; Bost M; Accominotti M;
Roussel AM
Laboratoire central de biochimie, hopital Lariboisiere, Paris, France.
Ann Biol Clin (Paris) (FRANCE) 1996, 54 (5) p181-7
In the last five years, there has been a renewal of
interest in the protective role of selenium in vascular
disorders, inspired by experimental evidence that this trace element could modulate
leukotriene and prostaglandin synthesis in both endothelial cells and platelets. In people
living in low-selenium areas, a relationship has been
established between a decrease in plasma selenium and an
increase in the risk of coronary disease, atherosclerosis, platelet hyperaggregability and
synthesis of proaggregant and proinflammatory compounds like thromboxane A2 and
leukotrienes. Selenium, as an essential part of glutathione peroxidase, takes part in the
reduction of hydrogen peroxides and lipid peroxides. The concentration of these peroxides,
in turn, regulates the activities of cyclooxygenase and lipooxygenase pathways, ultimately
influencing the production of eicosanoids and modulating the balance between a
proaggregatory and antiaggregatory state. Recent evidence shows that selenium,
via its action on glutathione peroxidase activity, may be primarily responsible for the
regulation of the endogenous hydroperoxide level. In human platelets, the activity of
glutathione peroxidase is particularly high and is very sensitive to the requirement of selenium. This sensitivity could explain why platelets of selenium-deficient subjects show increased aggregation, thromboxane
B2 production and synthesis of the lipoxygenase-derived compounds. In these deficient
subjects, selenium administration increases platelet
glutathione peroxidase activity and inhibits platelet hyperaggregation and leukotriene
synthesis. These results support the hypothesis that selenium
supplementation has a positive effect on platelet aggregation in selenium-deficient
subjects. In France, more than 10% of the population is selenium-deficient
and long-term supplementation with low doses of selenium
could have a beneficial effect on the prevention of both thrombosis and coronary heart
disease in these subjects. (35 Refs.)
Levander OA; Whanger PD
U.S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition
Research Center, MD 20705, USA.
J Nutr (UNITED STATES) Sep 1996, 126 (9 Suppl) p2427S-2434S
Information is presented regarding the approaches that have
been used to establish dietary recommendations for selenium
and iodine. In the case of selenium, activity of the
selenoenzyme glutathione peroxidase has served as a convenient biochemical endpoint for
judging nutritional status. However, there are differences of opinion among various
nutritionists as to whether full expression of this enzymatic activity is required for
adequate nutriture, thereby resulting in differences in dietary recommendations. Endpoints
for assessing selenium overexposure are much less
satisfactory, but toxicological standards for selenium have
nevertheless been established. Thus far, no nutritionists have attempted to shift the
paradigm for determining dietary selenium recommendations
away from prevention of deficiency disease to prevention of chronic degenerative disease
(e.g., cancer). In the case of iodine, urinary excretion of the element is the most widely
used endpoint for judging nutritional status. Numerous epidemiological surveys have been
conducted to determine the level of urinary iodine excretion that is consistent with
prevention of goiter, the most common endpoint of iodine deficiency. Because dietary
iodine is essentially quantitatively excreted in the urine, determination of the latter in
goitrous areas will allow an almost direct estimation of those intakes at risk of
developing deficiency disease. Iodine toxicity is complicated by the fact that some
persons are quite tolerant to the element whereas others are highly sensitive to it. There
are relatively complete data sets concerning exposure vs. human health effects for both selenium and iodine so that sounder bases probably exist for their
dietary recommendations than for many other trace elements.
Selenium is an essential trace element in nutrition for the
prevention of disease in humans. Epidemiological studies indicate an association between
low nutritional selenium status and increased risks of
cardiomyopathy, cardiovascular disease, and carcinogenesis in various sites of the body.
The role of selenium supplementation in the prevention and
treatment of AIDS-related pathology has been considered. Selenoproteins discovered in
mammalian cells may account for the essentiality of selenium
in the body's antioxidant defense; thyroid hormone function; immune system function,
particularly the cellular immunity; formation of sperm; and functioning of the prostate
gland. The seleno-organic compounds, primarily L-(+)-selenomethionine, generally are
recognized as safe and effective forms of selenium
supplementation. The nutritionally recommended dose of elemental selenium
is estimated at 50 to 200 mg per day. There is, however, increased discussion of a
pharmacological dose of selenium, significantly higher than
the nutritional dose of the microelement, to treat active conditions. One way of
increasing the tissue levels of selenium is to combine its
ingestible form with a nutrient bioavailability enhancing compound. (87 Refs.)
Arora AS; Gores GJ
Center for Basic Research in Digestive Diseases, Mayo Clinic and Foundation, Rochester,
Minnesota 55905, USA.
Semin Liver Dis (UNITED STATES) Feb 1996, 16 (1) p31-8
No abstract.
Jao SW; Shen KL; Lee W; Ho YS
Division of Colon and Rectal Surgery, National Defense Medical Center, Tri-Service General
Hospital Taipei, Taiwan, Republic of China.
Dis Colon Rectum (UNITED STATES) Jun 1996, 39 (6) p628-31
PURPOSE: This study was designed to determine the cancer
prevention and therapeutic effects of selenium on rats
treated with 1,2-dimethylhydrazine (DMH). METHODS: One hundred sixty Spraque-Dawley male
rats were divided into seven groups and received 20 mg/kg/week DMH, subcutaneously for 20
weeks. Two different dosages of selenium (8 and 4 ppm) were
administered to the rats through drinking water during DMH treatment (B and C groups) or
one month before and during DMH treatment (D and E groups). The rats of Groups A (control
group), B, C, D, and E were killed immediately after the last DMH injection. The incidence
of intestinal cancer in each group was compared. Eight ppm selenium
was also administered to rats after DMH treatment (Group F), and survival times were
observed and compared with Group G (treated with DMH only). RESULTS: Rats of Groups B and
D received 8 ppm selenium and had a significantly decreased
incidence of intestinal cancer (from 65.8 percent (Group A) to 33.3 percent (Group B) and
27.8 percent (Group D); P = 0.0225 and 0.0038). Rats receiving 4 ppm selenium
had a relatively decreased incidence of intecent (Group A) to 44.4 percent (Group C) and
47.1 percent (Group E) but P > 0.05). Survival time of Groups F and G showed no
difference. CONCLUSIONS: Eight ppm selenium provided via
drinking water has a significant intestinal cancer prevention effect in the presence of a
high dose of DMH (20 mg/kg x 20 weeks), and the cancer therapeutic effect of selenium is doubtful in this animal model.
Saito N
Nippon Rinsho (JAPAN) Jan 1996, 54 (1) p59-66
It is known that the peroxidation of LDL is a trigger for
developing arteriosclerosis. The oxidized LDL is produced by either oxidative stress or a
few oxidant. Selenium decreased in serum and some organs of stroke-prone spontaneously
hypertensive rats (SHRSP), which is a cofactor of glutamine peroxidase. Serum magnesium
decreased in patients with diabetes mellitus, with ischemic heart disease, with essential
hypertension and with cerebral vascular lesions. Calcium to magnesium ratio was higher in
some organs of SHRSP as compared to Wistar Kyoto rats (WKY). These changes accelerated
vascular lesions in SHRSP. (21 Refs.)
Crit Rev Food Sci Nutr (UNITED STATES) Apr 1997, 37 (3)
p211-28
Selenium (Se) was discovered 180 years ago. The
toxicological properties of Se in livestock were recognized first; its essential
nutritional role for animals was discovered in the 1950s and for humans in 1973. Only one
reductive metabolic pathway of Se is well characterized in biological systems, although
several naturally occurring inorganic and organic forms of the element exist. The amount
of Se available for assimilation by the tissues is dependent on the form and concentration
of the element. Se is incorporated into a number of functionally active selenoproteins,
including the enzyme glutathione peroxidase, which acts as a cellular protector against
free radical oxidative damage and type 1 iodothyronine 5'-deiodinase which interacts with
iodine to prevent abnormal hormone metabolism. Se deficiency has been linked with numerous
diseases, including endemic cardiomyopathy in Se-deficient regions of China; cancer,
muscular dystrophy, malaria, and cardiovascular disease have also been implicated, but
evidence for the association is often tenuous. Information on Se levels in foods and
dietary intake is limited, and an average requirement for Se in the U.K. has no been
established. Available data suggest that intake in the U.K. is adequate for all, except
for a few risk groups such as patients on total parenteral nutrition or restrictive diets.
(122 Refs.)
Mail Order Form Click Here!
View
Shopping Cart / Checkout